Honing tools are used for forming bores in various parts.
Bores may also be formed by grinding, but honing as is well known, is the method of choice because it is faster and consistently produces better bores, i.e., bores having closer tolerances to predetermined specifications.
A honing tool typically includes an elongate stone carried at the end of a mandrel; rotation of the mandrel about its longitudinal axis of symmetry effects simultaneous and corresponding rotation of the stone. The stone has longitudinally extending cutting edges that gradually form the desire bore in the part being honed as the stone is rotated.
Importantly, all known honing machines include means for driving the cutting stone radially outwardly with respect to the mandrel as the diameter of the bore being honed increases.
Typically, an elongate wedge member engages the radially inward side of the stone, and means are provided to axially advance the wedge member toward the stone so that the stone is driven radially outwardly as the wedge member advances.
The known honing machines of the prior art employ various sophisticated means for advancing the wedge member so that the radially outwardly advance of the cutting stone can be very carefully controlled. Importantly, one reason the stone-advancing means is so carefully controlled is so that the machine shop owner can set the machine to hone a part to a desired bore diameter and then leave the machine running while other tasks are performed. Thus, since the honing machine is unattended, means must be provided to insure that the machine does not produce a honed bore that has a diameter that exceeds specifications.
A typical sophisticated honing machine that does not require frequent monitoring by an operator is a large, free standing unit that costs over $5,000.00.
Many shops, however, do not employ the honing technique often enough to justify the major expense of a free standing honing machine.
Accordingly, there is a need for an inexpensive honing machine capable of producing high quality honed parts to precise specifications, but the prior art neither teaches nor suggests how such a machine could be built.